little 'ol 273

Just an observation -

One thing about 273 stock pistons - the wrist pins are insanely heavy, compare them to a late model 318. If you dont mind rebalancing the motor I'd look into getting some 318 wrist pins shortened to use with the 273 piston. I suspect mopar used these heavy wrist pins to add weight to the rotating assembly and allow them to get away with using a stock style bob weighted 318 crank. If you did this - it would add alot of rev potential and durability to the motor with very little changes. You would not have to use mallory metal unless I wrong.

I would imagine a cam similar to a 340 stocker might be a good choice - I'd look into getting some higher compression pistons as well. Use the closed chamber heads from the original motor or some #302 castings - you probably dont need to put bigger valves in. If you do, you should probably notch the top of the cylinders to make the best use of the larger valves as well. Definitely a mild bowl porting and port matching for sure on the heads.

Have fun sorting thru these ideas !